5 целых 2/9-(3 целых 1/9-2 целых 4/9)+5/9
............=5 2/9 - 3 1/9 + 2 4/9 + 5/9=(5-3+2)+(2/9-1/9+4/9+5/9)=4+10/9=4+1 1/9=5 1/9
= 5 2/9 - 3 1/9 + 2 4/9 + 5/9 = 7 11/9 - 3 1/9 = 4 10/9 = 5 1/9